甘蔗品质的分析方法:氯化物含量的测定.docx
甘蔗品质的分析方法:氯化物含量的测定1范围本部分描述了测定甘蔗汁中氯化物含量的原理、试剂、仪器设备、测定步骤、计算及结果表示、精 密度。本部分适用于采用化学法对甘蔗汁氯化物含量的测定。2规范性引用文件下列文件中的内容通过文中的规范性引用而构成本文件必不可少的条款。其中,注日期的引用文件, 仅该日期对应的版本适用于本文件;不注日期的引用文件,其最新版本(包括所有的修改单)适用于本 文件。GB/T 601化学试剂标准滴定溶液的制备GB/T 603化学试剂 试验方法中所用制剂及制品的制备GB/T 6682分析实验室用水规格和试验方法DB45/T XXXX. 4甘蔗品质的分析方法第4部分:蔗汁重力纯度的测定3术语和定义下列术语和定义适用于本文件。3. 1氯化物含量 ch I or i de content蔗汁本身含氯化物的量,通常用每100 g固溶物所含的氯离子(。-)克数表示。4原理在蔗汁中加入适当过量硝酸银溶液,以钱铁矶作指示剂,川硫银化钾溶液回滴过剩的Ag.。当CNS- 稍微过量时,与指示剂总Fe”结合呈现桃红色,即为滴定终点。5试剂3.1 除另有说明外,所用试剂均为分析纯,实验用水应符合GB/T 6682的要求。试验中所需标准滴定 溶液、制剂及制品,在没有注明其他要求时均按GB/T 601、GB/T 603的规定制备。3.2 硝酸银标准溶液(0. 1 mol/L):称取17. 0 g硝酸银用水溶解后,加水稀释至1 000 mL。用氯化 钾标定。注:标定:称取0.200 g分析纯氯化钾,溶于50mL水后,力111mL珞酸钾(50g/L)作指示剂,用硝酸银溶液滴定至浅 红棕色出现,而不立即消失为止。3.3 高钵酸钾饱和溶液。5. 4镂铁矶指示剂:量取5. 0mL硝酸(密度1.42g/cm3),加水稀释至50矶,加入钱铁矶(FeNHi (SOO 2-1211,0)配成饱和溶液。6. 5硫氧化钾标准溶液(0. 1 mol/L):称取9.8 g硫鼠化钾(KCNS),用水溶解并稀释至1 000 mLo 用0. 1 mol/L硝酸银溶液标定。6.6 乙醛。6.7 硝酸:密度(1.42 g/cm36仪器设备7. 1压榨机。8. 2 天平:感量 0.001g、0. 1 go6. 3 滴定管:25 mL、50 mL。6.4 容量瓶:50 mL、1 000 mL。6.5 吸量管:2 mL、5 mL、10 mL、20 mL、50 mL。6.6 烧杯:100 mL、500 mL。6. 7 磁力搅拌器:Or/min1400 r/min06.8 附温糖锤度计或折光锤度计。6.9 精密温度计:0C50C,精度0.6. 10 筛网:150 卬1 (100 R) o7测定步骤7.1 试样的测定将压榨的蔗汁混匀后过150 um (100目)筛网漉去蔗渣,吸取10mL50mL蔗汁于500mL烧杯中, 加水稀释至约200mL。再加入15mL硝酸(5.7),从滴定管中放入过量0. 1 mol/L硝酸银溶液(5.2), 磁力搅拌,逐滴加入饱和高钵酸钾溶液(5.3),直至溶液呈灰黄色,加入2 mL钱铁矶指示剂(5.4), 再加5mL乙醛(5.6) o再用0. 1 mol/L硫锐化钾溶液(5.5)回滴,直至乙酸层呈现桃红色为止。7.2 蔗汁锤度按DB45/T XXXX.4规定执行。8计算及结果表示蔗汁中氯化物含量CL以每100 g固溶物所含的氯离子质量(g)表示,按式(1)结算:匕)xCx0.03456xl00 C _x 1 )VxdxB式中:C1蔗汁中氯化物含量,单位为克(g);匕加入蔗汁中硝酸银溶液体积,单位为亳升(mL);V2滴定消耗硫氟化钾溶液体积,单位为亳升(mL);V-蔗汁体积,单位为亳升(mL);C硝酸银溶液浓度,单位为摩尔每升(mol/L);d一蔗汁视密度(20 ),用蔗汁锤度查附录A得到;B一蔗汁锤度(20 ),单位为锤度dBx);0. 03456Inunol Cl-质量,单位为克(g)。取平行测定值的算术平均值为测XX果,保留小数点后三位。9精密度在重复条件下获得的两次独立测试结果的绝对差值不大于这两个测定值的算术平均值的10%。附录A(资料性)蔗汁锤度-视密度对照表蔗汁锤度-视密度对照表见表A. 1。表A.1锤度-视密度对照表锤度(0Bx)视密度(20 )锤度(°Bx)视密度(20 )锤度(°Bx)视密度(20 X?)锤度(°Bx)视密度(20 C)锤度(°Bx)视密度 (20 )0.00. 997170. 10. 997560.20. 997950.30. 998340.40. 998720.50. 999110.60. 999500.70. 999890.81.000280.91.000671.()1.001061. 11.001451.21.001841.31.002231. 41.002611.51. 003001.61.003391.71.003781.81.004171.91.004562.01. 004952. 11.005342.21.005742.31.006132.41.006522.51.006912.61.007302.71.007692.81. 008092.91. 008483.01.008873. 11.009273.21.009663.31.010063.41.010453.51.010843.61.011243.71.011633.81.012033.91.012434.01.012824. 11.013224.21.013614.31.014014.41.014414.51.014804.61.015204.71.015604.81.016004.91.016405.01.016805. 11.017195.21.017595.31.017995.41.018395.51.018795.61. 019195.71.019555.81.019995.91.020406.01. 020806. 11.021206.21.021606.31.022006.41.022416.51.022816.61.023216.71.023626.81. 024026.91.024427.01.024837. 11.025237.21.025647.31.026047.41.026457.51. 026857.61.027267.71.027667.81. 028077.91. 028488.01.028888. 11. 029298.21.029708.31.030118.41.030528.51.030938.61.031338.71.031748.81.032158.91.032569.01.032979. 11.033389.21.033799.31.034209.41.034619.51.035039.61.035449.71.035859.81. 036269.91. 0366710.01.0370910. 11.0375010.21.0379110.31.0383310.41.0387410.51.0391610.61.0395710. 71.0399910.81.0404010.91.0408211.01.0412311. 11.0416511.21.04207il.31.0424811.41.0429011.51.0433211.61.0437311.71.0441511.81.0445711.91.0449912.01.0454112. 11.0458312.21.0462512.31.0466712.41.0470912.51.0475012.61.0479312.71.0483512.81.0487712.91.0191913.01.0496113. 11.0500313.21.0504613.31.0508813.41.0513013.51.0517213.61.0521513.71.0525713.81.0530013.91.0534214.01.0538514. 11.0542714.21.0547014.31.0551214.41.0555514.51.0559814.61.0564014.71.0568314.81.0572614.91.05768表A. 1锤度-视密度对照表(续)锤度(°Bx)视密度(20 C)锤度(°Bx)视密度(20 )锤度(°Bx)视密度(20 )锤度(°Bx)视密度(20 )锤度(°Bx)视密度(20 )15.01.0581115. 11. 0585415.21. 0589715.31. 0594015.41.0598315.51.0602615.61. 0606915.71.0611215.81.0615515.91.0619816.01.0624116. 11.0628416.21.0632716.31.0637016.41.0641416.51. 0645716.61.0650016.71. 0654416.81.0658716.91.0663017.01.0667117. 11.0671717.21.0676117.31. 0680417.41. 0684817.51.0689117.61.0693517.71.0697817.81.0702217.91.0706618.01.0711018. 11.0715318.21.0719718.31.0724118.41.0728518.51.0732918.61.0737318. 71.0741718.81.0746118.91.0750519.01.0754919. 11.0759319.21.0763719.31.0768119.41.0772519.51.0776919.61.0781419.71.0785819.81.0790219.91.0794720.01.0799120. 11.0803520.21.0808020.31.0812420.41.0816920.51.0821320.61.0825820. 71.0830220.81.0834720.91.0839221.01.0843621. 11.0848121.21.0852621.31.0857121.41.0861621.51. 0866021.61.0870521.71.0875021.81.0879521.91.0884022.01.0888522. 11.0893022.21.0897522.31.0902022.41.0906622.51.0911122.61.0915622.71.0920122.81.0924722.91.0929223.01.0933723. 11.0938323.21.0942823.31.0947323.41.0951923.51.0956423.61. 0961023.71.0965623.81.0970123.91.0974724.01.0979224. 11.0983824.21.0988424.31.0993024.41.0997624.51. 1002124.61. 1006724.71. 1011324.81. 1015924.91. 1020525.01.1025125. 11. 1029725.21.1034325.31. 1038925.41. 1043525.51. 1048225.61. 1052825.71. 1057425.81. 1062025.91. 1066726.01. 1071326. 11. 1075926.21. 1075926.31. 1080626.41. 1089926.51. 1094526.61. 1099226.71. 1103826.81. 1108526.91. 1113127.01.1117827. 11.1122527.21. 1127227.31. 1131827.41. 1146527.51. 1141227.61. 1145927.71. 1150627.81. 1155327.91. 1160028.01. 1164728. 11. 1169428.21. 1174128.31. 1178828.41. 1183528.51. 1188228.61. 1192928.71. 1197728.81. 1202428.91. 1207129.01.1211929. 11. 1216629.21.1221429.31. 1226129.41. 1230829.51. 1236529.61. 1240429.71. 1245129.81. 1249929.91. 1254630.01. 1259430. 11. 1264230.21. 1269030.31. 1273730.41. 1278530.51. 1283330.61. 1288130. 71. 1292930.81. 1297730.91. 1302531.01.1307331. 11. 1312131.21. 1316931.31. 1321731.41. 1326631.51. 1331431.61. 1336231.71.1341031.81. 1345931.91. 1350732.01. 1355532. 11. 1360432.21. 1365232.31. 1370132.41. 1374932.51. 1379832.61. 1384632.71. 1389532.81. 1394432.91. 13992